Portable pedestrian navigation system

ABSTRACT

A portable pedestrian navigation system including a computing device, a proximity sensor and an output device. The proximity sensor and the output device are communicatively coupled to the computing device and the computing device is adapted for receiving environmental data at least from the proximity sensor. Based on the environmental data, A candidate guide entity near the pedestrian is identified. Based on the environmental data, the output device is used for guiding the pedestrian in accordance with a movement of the identified candidate guide entity as a selected guide entity.

BACKGROUND

Embodiments of the present invention relate to computer-assistedpedestrian navigation, and more particularly, to computer-assistednavigation of a visually impaired person.

A visually impaired pedestrian may find it difficult, in ordinarycircumstances, to navigate freely and independently while reliablyavoiding obstacles in a crowded environment (whether objects orpersons). Various techniques providing partial indoors and outdoorsnavigation support have been developed in attempts to meet these needs.Some solutions use geographical information and/or different kinds ofsensors and/or a wearable electronic image acquisition system to analyzea person's environment for obstacles and communicate navigationinformation, including obstacle information, to a user via tactilesignals.

SUMMARY

Embodiments of the invention may provide a portable pedestriannavigation system, a method of operating such a system, and a computerprogram product implementing such a method. Additional embodiments ofthe invention are given in the dependent claims. Embodiments of thepresent invention can be freely combined with each other if they are notmutually exclusive.

In one aspect, an embodiment of the invention relates to a portablepedestrian navigation system to be ported by a pedestrian. The systemincludes a computing device, a proximity sensor and an output device.The proximity sensor and the output device are communicatively coupledto the computing device. The computing device receives environmentaldata at least from the proximity sensor. Based on the environmentaldata, the computer system identifies a candidate guide entity near thepedestrian. Based on the environmental data, the computer system usesthe output device for guiding the pedestrian in accordance with amovement of the identified candidate guide entity as a selected guideentity.

In another aspect, an embodiment of the invention relates to a method ofoperating a portable pedestrian navigation system to be ported by apedestrian. The navigation system includes a computing device, aproximity sensor and an output device. The proximity sensor and theoutput device are communicatively coupled to the computing device. Thecomputing device includes a processor and memory. The memory storescomputer-executable instructions which, when executed by the processor,cause the computing device to perform certain functions. The computingdevice receives environmental data at least from the proximity sensor.Based on the environmental data, the computing device identifies acandidate guide entity near the pedestrian. Based on the environmentaldata, the computing device uses the output device for guiding thepedestrian in accordance with a movement of the identified candidateguide entity as a selected guide entity.

In a further aspect, an embodiment of the invention relates to acomputer program product for operating a portable pedestrian navigationsystem to be ported by a pedestrian. The navigation system includes acomputing device, a proximity sensor and an output device. The proximitysensor and the output device are communicatively coupled to thecomputing device. The computing device includes a processor and memory.The computer program product includes a computer-readable medium and aset of computer-executable instructions incorporated therewith. Thecomputer-executable instructions, when executed, cause the computingdevice to perform certain functions of a method. The computing devicereceives environmental data at least from the proximity sensor. Based onthe environmental data, the computing device identifies a candidateguide entity near the pedestrian. Based on the environmental data, thecomputing device uses the output device for guiding the pedestrian inaccordance with a movement of the identified candidate guide entity as aselected guide entity.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the following, embodiments of the invention are explained in greaterdetail, by way of example only, making reference to the drawings inwhich:

FIG. 1 depicts a schematic usage situation of a portable pedestriannavigation system;

FIG. 2 is a schematic overview of a portable pedestrian navigationsystem; and

FIG. 3 visualizes a method of operating a portable pedestrian navigationsystem.

DETAILED DESCRIPTION

Computer-implemented real-time recognition of obstacles and otherobjects within a changing personal environment is a computationallydemanding task with a potential for severe damage and injuries in casesof performance failures. Therefore, there is a need for a mobilepedestrian navigation technology which is more secure and consumes lesscomputational resources.

The current disclosure addresses these issues by providing a systemwhich is capable of providing a secure guidance for visually impairedpeople that need to walk and arrive at a destination. In an embodimentof the invention, a system is provided that is capable of combininginformation coming from wearable proximity sensors (like bracelets orshoes with other sensors and/or actors that can interact with a user;for example, devices that vibrate) with further available information,for example from external mobile devices or a GPS navigator unit, todetect obstacles and to recognize that there is a person who is walkingin the same direction and at the same speed as the user.

The system may be implemented by a software component (“the plugin” inthe following) that is plugged on top of a traditional mobile pedestriannavigation device. The plugin is able to use the existing navigationhardware and/or collaborate with external devices to provide the userwith a walking assistance.

In an embodiment, the visually impaired person may wear a wearabledevice, for example bracelets or shoes with proximity sensors,positioned on both arms and legs or shoes, and actors, vibrators orother tactile output devices capable of indicating a direction. Acomputing device analyzes the sensor signals together with navigationdata (for example, GPS data) and uses the output devices to indicate adirection to the user based on a movement of the person or externaldevice chosen as a guide. Outputs may be of positive type (go ahead,turn right or left), or of negative type (stop; for example, whenapproaching an obstacle).

The person chosen as a guide can be made aware of being selected as aguide in case the chosen person carries a further mobile computingdevice, which may have an additional guide software installed, or whichmay be capable of receiving a notification message (e.g. via SMS)indicating that a guiding sequence has been requested or started. Theplugin may be capable of querying the guide software on the nearbydevice to request a candidate's destination and promote the candidate asa “selected guide”.

In an embodiment, in order to set a route for the navigation system, theplugin leverages an explicit declaration from the user, informationcoming from a calendar event, or an internal extrapolation function ofthe plugin or system that can provide sections of an estimated routebased on the current walking direction.

The navigation system may collect information about a plurality ofavailable candidate guides or concatenate a series of route sectionsprovided by the movement of a plurality of selected guide entities forproviding a comprehensive walking assistance. The system may alsoprovide different levels of optimization, for example, by using a guideranking based on a walking speed or an available or derived indicatorfor reliability of information.

In an embodiment, at regular time intervals, the system may revalidatethe chosen guide entity by checking, for instance, if the guide stopssomewhere, and choosing a new guide if necessary and available.

Optionally, the guide may be billed or rewarded using a function of theguide software which is capable of contacting a vendor or bonus system.

Embodiments of the invention may have the advantage that a person (e.g.a visually impaired person or a person visiting an unfamiliar place) canleverage on the view experience of another person walking in the same ora desired direction to avoid obstacles and arrive at a destination in amore secure way. Embodiments of the invention use indicators of humanappearance and/or the presence of a mobile computing ortelecommunications device to recognize a person who might serve as aguide for the user of the portable pedestrian navigation systemdisclosed herein.

Expressions such as “near the pedestrian” used herein to indicate aproximity are to be construed as referring to the maximum range withinwhich the portable pedestrian navigation system is capable ofidentifying a candidate guide entity (the “sensing range”).

A “guide entity” may be a human who is available and/or acting as aguide person for the user of the navigation system, and/or a mobileelectronic device, preferable a computing device, which is carried bysuch available or active guide person and is capable of providinginformation to the portable pedestrian navigation system which can beused by the computing device of the navigation system to determinewhether the device and/or the guide person is eligible for guiding theuser of the navigation system and/or to guide the user of the navigationsystem in accordance with a movement of the guide person and/or themobile device. The expression “person associated with the guide entity”denotes either the guide person if the guide entity is a guide person,or a guide person carrying or owning the guide computing device if theguide entity is a guide computing device.

The expression “guiding the pedestrian in accordance with a movement”refers to providing a signal to the user of the portable pedestriannavigation system which indicates a direction into which the user wouldhave to walk to arrive at a current place of the guide entity whileavoiding the same obstacles as the guide entity avoided to reach thecurrent place of the guide entity. The direction(s) thus provided to theuser may differ from the route actually taken by the guide entity, forinstance in cases when the guide entity's route gets blocked by atransient obstacle. However, it may be possible to reduce thecomputational effort for determining a route to be pursued by the userof the navigation system in cases when an obstacle can be avoided bytaking essentially the same route as the guide entity did previously.

“Environmental data” include any signals and data received by thecomputing device from sensors and/or communicational devices, unitsand/or interfaces of the portable pedestrian navigation system. This mayinclude, for example and without limitation, a camera image of theuser's environment as well as a response to an availability request forguiding the user of the navigation system.

Non-limiting examples of the computing device include a cell phone, asmartphone, a tablet computer or another mobile computer systemcomprising dedicated pedestrian navigation hardware.

The term “proximity sensor” refers to any device which is capable ofoutputting a signal which encodes structural information descriptive ofsolid and/or liquid structures such that the encoded structuralinformation can be decoded by the computing device. The proximity sensorshould be capable of detecting said structures within a preferredmaximum range of one or more tens of meters to one or more hundreds ofmeters, but not necessarily more than one kilometer.

A “guide sequence” or “guiding sequence” is understood herein as anynavigation signals provided to the guided pedestrian by the computingdevice of the portable pedestrian navigation system using the outputdevice. A “identification sequence” is understood herein as anycomputer-implemented analysis performed by the computing device of theportable pedestrian navigation system which results in a positive ornegative classification of a portion of the environmental data asrepresenting the presence of a guide entity, irrespective of whether theidentified entity is eligible for acting as a guide for the user of thesystem or not.

It may be beneficial to allow the computing device analyze whether anidentified candidate guide entity is suitable for being selected as theselected guide entity. For this purpose, the computing device may storein its memory one or more eligibility criteria, which may be managed ina user-configurable profile and will be described in more detail below.

According to embodiments, the system may further include a wirelesscommunications unit. The wireless communications unit may becommunicatively coupled to the computing device. The computing devicemay further be adapted for receiving the environmental data from thecommunications unit. The identification of the candidate guide entitymay include implementing a method. The method may include generating anavailability request for guiding the pedestrian. The method may furtherinclude broadcasting the availability request using the wirelesscommunications unit. In response to the broadcast, the method mayreceive a response from a candidate computing device. Based on theresponse, the method may select the candidate computing device as theselected guide entity.

This may have the advantage that the pedestrian may be guided inaccordance with the movement of the selected computing device inreplacement or addition of a guide person. The movement of a guidecomputing device (i.e. the candidate computing device which was selectedas the selected guide entity) may be less prone to errors than a passivedetection of a guide person using the proximity sensor, because thenavigation system may receive wireless signals from the guide computingdevice which may be used to update the current position of the guidecomputing device. The guide computing device may also serve as a backupguide entity in case that the computing device of the navigation systemloses track of the guide person via the proximity sensor, and viceversa, the guide person may serve as a backup guide entity in case thatthe computing device of the navigation system loses track of the guidecomputing device via wireless communication unit.

The availability request may comprise a request for any informationwhich may be used by the computing device to determine whether thecandidate computing device and/or a candidate guide person associatedwith the guide computing device is eligible for guiding the user of thenavigation system. Such information may include, without limitation, anidentifier (name) of the guide computing device and/or the candidateguide person associated with the guide computing device; an age, agender or a walking velocity of the candidate guide person; anidentifier indicating the candidate guide person's willingness to act asa guide; a timestamp indicating data currentness of information relatedto the candidate guiding person; a length of a route section on whichthe candidate guide person is expected to be available for guiding; apotential time and/or place of encounter of the pedestrian with thecandidate guide person; or a combination thereof.

According to some embodiments, the wireless communications unit has amaximum range between 10 and 250 meters. A maximum range of at least tenmeters may ensure that the guided person may speak to the guide personassociated with the selected guide computing device, while a largermaximum range may allow for an early search for a guide entity for asubsequent route section, and hence, an early initialization of a guidedcontinuation for the current route section.

According to embodiments, the wireless communications unit comprises acommunications interface according to one of the following: IEEE 802.15;IEEE 802.11; Wireless USB; wireless ad hoc network; DASH7; RuBee;Z-Wave; a mobile telecommunications standard; or a combination thereof.

IEEE 802.15 and IEEE 802.11 may be beneficial for providing a large andwidespread number of computing devices with communications capabilitieswithin the required range for contacting a candidate computing device.IEEE 802.15 devices include, for example, Bluetooth and ZigBee devices,while IEEE 802.11 device offer a Wireless LAN (WLAN) capability. Theterm “mobile telephony interface” designates at least the circuitry forcommunicating via a standard cellular phone network using technologiessummarized under one or more of the exemplary cellular network standardsGSM 2G, 3G, 4G, 5G and the like. Widespread mobile computing devicessuch as smartphones and tablet computers use a combination of a mobiletelephony interface and one or more IEEE 802 devices (e.g. an LTEtelephony, WLAN and Bluetooth). RuBee uses magnetic waves and maytherefore be less sensitive to distortions caused by metal objects.Z-Wave and RuBee may be beneficial for offering enhanced power savingcapabilities.

According to embodiments, the computing device is further adapted fordetecting a coincidence of position, direction and/or velocity between amovement of an object detected using the proximity sensor and a movementof the candidate computing device, the computing device being furtheradapted for performing the guidance in accordance with the movement ofthe detected object as an auxiliary guide entity. According toembodiments, the computing device is adapted for performing theidentification of the candidate guide entity as a person by analyzingthe environmental data with a person recognition algorithm.

These embodiments may be advantageous for enabling the computing deviceto determine whether a candidate device is actually carried by a walkinghuman, and/or whether a candidate device detected using the wirelesscommunications unit is carried by a candidate person detected using theproximity sensor.

According to embodiments, the computing device is further adapted forperforming the guidance of the pedestrian in accordance with a route tobe taken by the pedestrian, the identification of the candidate guideentity comprising determining, based on the environmental data, whethera route expected to be taken by the candidate guide entity coincideswith at least a section of the route to be taken by the pedestrian.

This may enable the computing device to guide the pedestrian inaccordance with the movement of the guide entity along merely a routesection instead of waiting for a guide who happens to walk to the samedestination as the guided person. An eligibility criterion for acceptingthe candidate guide entity may comprise rejecting the candidate if theestimated common route section is shorter than a user-defined thresholdlength (e.g., 100 meters).

According to embodiments, the computing device is further adapted fordetermining, in case that an updating condition is fulfilled, an updatedselected guide entity by repeating the identification of the candidateguide entity, the updating condition relating to a detection of one ofthe following events in conjunction with the selected guide entity: aninterruption of movement for more than a predefined period; a deviationfrom an expected route by more than a predefined distance; a movementwith a velocity out of a predefined velocity range; a movement out of adetection range of the navigation system; an approach of a prospectivepoint of separation from the pedestrian by less than a predefineddistance; or a combination thereof.

This may be beneficial for allowing the computing device to guide theuser of the navigation system in accordance with the movement of asequence of guiding entities, and thus provide the safety andreliability of a human guide over a longer portion of the route. Forinstance, the determination of an updated selected guide entity may beperformed on a regular basis (e.g. every 30 seconds, predetermined forthe current walk or according to a default configuration), in ascheduled manner (e.g. 10 minutes after starting the guidance or whenreaching a predetermined location), or based on a detected event (e.g.when the guide entity is moving out of the sensing range of theproximity sensor, moving too fast or in a wrong direction).

According to embodiments, the computing device is further adapted forreceiving a preference information of the pedestrian and performing theguidance of the pedestrian in accordance with the preferenceinformation. Preference information refers to any indication, forexample, received by the user as a condition for a particular present orfuture guidance procedure or present in the memory of the computingdevice as a general or default setting, which the computing device mayuse to prioritize route options for a particular guidance. Thepreference information may include, without limitation, a desiredarrival time, one or more desirable and/or undesirable geographicallocations, and/or relative and/or categorized indications such as airquality, number density of pedestrians, motorized vehicles, etc.

In one example, the preference information includes a desired arrivaltime of the pedestrian. The computing device may then calculate anestimated arrival time of the selected guide entity and perform thedetermination of an updated selected guide entity in case that theestimated arrival time of the selected guide entity deviates from thedesired arrival time of the pedestrian by more than a predeterminedthreshold period. This may enable to perform the guidance with a higherprobability to arrive at the desired destination on time. For thisfunction, the computing device needs to have received, before or duringthe guidance procedure, an input specifying the pedestrian's desireddestination and arrival time.

The desired destination location and/or arrival time may be specified invarious ways, for example as a user input or a calendar event. Arrivaltime and/or destination may be reconfigurable so that the guidance mayresult in a more precise navigation, for example to a specific entranceof a sports stadium. An offset period may be provided, for example as asetting in the user-configurable profile, to obtain the possibility of abuffer time. The buffer time may be useful, for example, where thepedestrian wishes to be navigated so as to usually arrive at thedestination ten minutes earlier than the time which is assigned to theevent.

In particular, the computing device may be configured to discern betweenan event time and the desired arrival time. This may allow the computingdevice to guide the pedestrian so as to arrive at the destination atessentially the specified desired arrival time, while on the other hand,in case that the only known time is an event time, to navigate thepedestrian to arrive at the configured offset period relative to theknown event time. The offset period may be specified with a sign, i.e.as a negative number indicating that the pedestrian wishes to arriveearlier than the event time, or as a positive number indicating that thepedestrian wishes to arrive later than the event time. Alternatively,the offset period may be specified without a sign and the condition“earlier” or “later” may be implemented as a logical attribute in thiscase. A later arrival may be beneficial, for example, if the pedestrianexpects the event to start with a large crowd which gets smaller after awhile (e.g. a sports event or music concert), or for social reasons.

The threshold period may also be specified, for example as a negativenumber, to indicate that the guide entity should be changed so as toenable an arrival which the pedestrian considers not too early; as apositive number to enable an arrival which the pedestrian considers nottoo late; and/or a sign-less number to enable an arrival approximatelyon time, which may be beneficial, for example, for events where thepedestrian wishes to arrive in a relaxed condition or deems an arrivalon time to be less important. An approximate arrival time window thusspecified may also facilitate a prioritization of multiple availablecandidate guide entities, so that the computing device may select theguide entity which matches the time window best. The approximate arrivaltime window may also prevent the computing device from searching foranother candidate guide entity too aggressively, for example if theguide entity is calculated to miss the destination by only one minute.

In another example, the preference information comprises one or moredesirable and/or undesirable geographical locations. This may providevarious benefits to the pedestrian, such as the ability to walk onpreferred routes which the pedestrian knows—for example, rather smoothslopes, a small number of obstacles, a route with a preferred numberdensity of other pedestrians, etc. Likewise, the pedestrian may avoidroutes through difficult or dangerous areas.

Handling of desirable and/or undesirable geographical locations mayrequire the computing device to be capable of or configured forcalculating routes on metadata-enhanced map data (e.g. names of streetsor city quarters, current traffic densities, etc.) In particular, thedesirable and/or undesirable geographical locations may be: stored as ageneral setting for all guidance events in a user-configurable profile;for example, as a file or database entry including a list or mapmetadata; received by the computing device as an event-specificinformation for a particular future or current guidance procedure;time-independent and/or time-dependent, for example to avoid walkingthrough a park at a predefined time of day, to avoid walking a steeproute during winter, to use a pedestrian zone instead of streets with ahigh density of motorized traffic during predefined or user-configurerush hours, etc.

Accordingly, the user may configure, via a user interface, and store thepreference information in a profile stored in the memory of thecomputing device. The user may toggle binary preference indicators suchas “avoid locations with bad air quality”, “prefer byroads” or “preferroutes with more pedestrians”, and/or select between differenttemplates, such as a setting “Automotive traffic” with an attacheddropdown menu offering the options “Low”, “Any” and “Avoid rush hours”.The computing device may evaluate possible routes according topreconfigured and/or current map data and/or current and/or averagetraffic data received via an internet connection. Relative informationsuch as “high number density of pedestrians”, may be decided based onappropriate threshold values provided, for example as a preconfigureddefault setting and/or information received via a user input.

In case the computing device determines that the guide entity enters anundesirable geographic location such as an area which is marked as a“potentially dangerous district” or approaches a construction site, thecomputing device may calculate and navigate the pedestrian along analternative route and/or determine an updated selected guide entity asdescribed before.

According to embodiments, the system is further adapted for performingthe identification of the candidate guide entity based on one of thefollowing: an age, a gender or a walking velocity of a candidate guideperson; an identifier indicating the candidate guide person'swillingness to act as a guide; a timestamp indicating data currentnessof information related to the candidate guiding person; a length of aroute section on which the candidate guide person is expected to beavailable for guiding; a potential time and/or place of encounter of thepedestrian with the candidate guide person; or a combination thereof.

Such information may be received via a response to an availabilityrequest which was previously broadcast by the navigation system, acellular communications network and/or an internet connection. Some orall of the ranges may be managed by the computing device in auser-configurable profile stored in its memory.

The eligibility of a guide can be assessed even when the persontransporting the candidate computing device does not have the guidingapplication installed. In such cases, the response may include a networkidentifier of the candidate computing device, where identifying theguide person includes submitting a request to an information system toquery whether a person assigned to the network identifier is willing toact as a guide. In an example (see also Example 9 further below), thecandidate computing device is a mobile phone and the response containsthe International Mobile Subscriber Identity (IMSI) of the SIM cardassigned to a user of the candidate computing device. The computingdevice is configured to reject the candidate if the response or thenetwork query reveals that the candidate is not willing to act as aguide.

According to embodiments, the computing device is further adapted forperforming the guidance additionally based on a route assigned to theguide entity and/or a route calculated for the pedestrian in case theguidance cannot be continued based on the environmental data. Accordingto embodiments, the computing device is further adapted for performingthe guidance based on the route calculated for the pedestrian only ifthe guidance cannot be continued based on the route assigned to theguide entity.

These embodiments may ensure that the guidance can be continued with analternative source of navigation if a preferred guiding source isunavailable. It is pointed out, however, that the environmental datareceived via the proximity sensor, as long as they are available, shouldbe treated with the highest priority as environmental conditions maychange, for example after the guide has passed an obstacle or after thecalculation of a route to pursued by the pedestrian.

According to embodiments, the system further comprises a locationsensor, the location sensor being communicatively coupled to thecomputing device, the computing device being adapted for receivinglocation data from the location sensor and performing the guidanceand/or the identification using the location data.

This may enable the computing device to guide the pedestrian with a highaccuracy and align the current position and/or route with map datastored in its memory. Preferably, the location sensor is asatellite-based navigation system receiver such as a GPS receiver.

According to embodiments, the system further includes an interface forreceiving a navigation specification. The interface is communicativelycoupled to the computing device and includes one of the following: amicrophone; a tactile input device; a wireless communications unit; awired communications unit; and a combination thereof. The computingdevice is adapted for performing the guidance and/or the identificationbased on the received navigation specification.

A navigation specification may include, without limitation, calendardata such as the candidate guide's and/or the guided pedestrian'sintended time and/or place of arrival and/or departure; the guide'sintended route and/or a previously calculated route to be taken by theguided pedestrian; forecasted and/or measured weather data; and/or acommand by the user. This may enable the computing device, amongst otherpotentially advantageous functions, to predetermine a route for the userof the navigation system which takes most advantage of presumablyavailable guide persons; to output an alarm signal to notify the userthat departure is due to join a particular guide person on the way; tocalculate an alternative route if the guided user deviates from anoriginally calculated or received route; and/or to accept commands, forexample to spontaneously change the route, the destination and/or theguide entity.

According to embodiments, the proximity sensor comprises one of thefollowing: an optical sensor, an infrared sensor, a radar sensor, anultrasonic sensor; or a combination thereof. These exemplarytechnologies may provide the computing device with high-qualityenvironmental data to enable a comprehensive, reliable and highlyresolved detection of objects, obstacles and/or persons near thepedestrian.

According to embodiments, the output device includes one of thefollowing: a tactile actor; a loudspeaker; a visual display; or acombination thereof. These technologies may provide computer-assistednavigation to the user with particular advantages depending on thespecific usage situation. For example, a loudspeaker may enable a moreprecise navigation output while a tactile actor may be more reliable ina loud environment (e.g. a busy street). A visual display may enablecomfortable navigation for a user who is not visually impaired, butwants to use computer-assisted navigation to walk in an unfamiliarenvironment.

According to yet another aspect, the invention relates to a secondcomputer program product (which is also referred to herein as a “guideapplication”, “guide software” or “guide plugin”). The second computerprogram product includes a second set of computer-executableinstructions incorporated with a second computer-readable medium. Thecomputer-executable instructions of the second set are adapted to causea further computing device, when executed by a processor of the furthercomputing device, to receive an availability request for guiding thepedestrian, and in response to receiving the request, generate aresponse from a candidate computing device. The response includes one ofthe following: an age, a gender or an expected walking velocity of anavailable guiding person; an identifier indicating the available guidingperson's willingness to act as a guide; a timestamp indicating datacurrentness; time and/or place of starting and/or arrival; a route to betaken by the available guiding person; an expected time and place ofencounter; an identifier for the available guiding person; or acombination thereof.

Such guide application may enable the further computing device togenerate and transmit a response to an availability request from theportable pedestrian navigation system. The response may includeuser-configurable content which may be stored as a guide profile in thememory of the further computing device.

According to embodiments, the computer-executable instructions of thesecond set are further adapted to cause the further computing device,when executed by the processor of the further computing device, toreport, upon completion of the guidance, characteristics of the guidanceto a computing system (typically a remote server in a network) forbilling or rewarding the available guiding person. This may increase thepopularity of the guide application and may therefore have the technicaleffect of increasing the probability that the user of the portablepedestrian navigation system receives a response to an availabilityrequest. Especially when moving in a crowded area, the user may benefitfrom the ability to select the most suitable guide for a givennavigation task.

According to embodiments, the method further includes performing thefollowing steps using the portable pedestrian navigation system. Theportable pedestrian navigation system receives navigation informationdescriptive of at least a desired destination to be reached by thepedestrian. The portable pedestrian navigation system calculates a routefor the pedestrian to reach the destination from the current position,and broadcasts an availability request for guiding the pedestrian. Inresponse to the broadcast, the portable pedestrian navigation systemreceives a response from a candidate computing device. Based on theresponse, the portable pedestrian navigation system selects thecandidate computing device as the selected guide entity. At a regulartime interval, portable pedestrian navigation system determines whetheran updating condition is fulfilled, and if the updating condition isfulfilled, determines an updated selected guide entity by repeating theidentification of the candidate guide entity. The portable pedestriannavigation system reports, upon completion of the guidance,characteristics of the guidance to a computing system for billing orrewarding a person associated with the guide entity.

Now turning to the drawings, FIG. 1 is a schematic illustration whichshows an exemplary situation where a guided person 100 (depicted as avisually impaired person 100 at the center of the image) uses a portablepedestrian navigation system 200 to walk along a route by following aguide entity 102 (in the foreground; either a guide person 102 asdepicted or a guide computing device 102 carried by the guide person102) that was previously identified 302 and selected by the portablepedestrian navigation system 200. The guide person 102 and the guidedperson 100 are crossing a street, wherein the guide person 102 iswalking a few meters ahead of the guided person 100, within a sensingrange of the navigation system 200. Another person 104 within thesensing range of the navigation system 200 is running on the sidewalk inthe background of the drawing. The running person 104 was not selectedas a guide by the navigation system 200 because the navigation system200 previously determined that the running person 104 has a too highvelocity to be followed by the guided person 102.

The use situation of the portable pedestrian navigation system 200 usedby pedestrian 100 is only a limited, non-exhaustive example by whichsome of the possible functions of the system 200 can be demonstrated.Numerous further functions and effects of the portable pedestriannavigation system 200 will become apparent in the following examples ofuse. All elements of all examples given may be freely combined whereverthis is technically possible.

EXAMPLE 1

The computing device 202 uses the proximity sensor 210 to detect anobject which is moving into the same direction as the pedestrian 100 orinto a desired direction at a speed within a preferred speed range.Optionally, the computing device 202 executes a person recognitionalgorithm on the received environmental data which analyzes, forexample, the dimensions or appearance of the detected object todetermine a probability that the detected object is a human.

In this example, it is not necessary for the computing device 202 toknow a route which was previously determined to be followed by theguided person 100 or a destination which the guided person 100 issupposed to approach. It is sufficient that the computing device 202 canuse the proximity sensor 210 to track the movement of the detected guideentity 102 so that it can direct the guided person 100 on essentiallythe same way as the guide entity 102. This may allow the guided person100 to walk along a route which has a high probability of being free ofobstacles.

In an alternative situation, the computing device 202 compares thedirection of the detected object to a route which was calculated orreceived for the guided person 100 to reach a desired destination.Additionally, the computing device 202 has stored in its memory 206 apreferred velocity range at which the guided person 100 is supposed tofeel comfortable to walk. If, for instance, the direction of thedetected object is within plus-minus 10 degrees relative to the currentwalking direction according to the predetermined route and its detectedvelocity is within the preferred velocity range, the computing device202 accepts the detected object as a selected guide entity 102 andstarts to direct the guided person 100 in accordance with the routewhich is actually pursued by the selected guide entity 102 instead ofthe previously determined route.

In both alternatives of the current example, the computing device 202continues to cause the guided person 100 to follow the selected guideentity 102 until, for instance, it receives a contrary navigationspecification by the guided person 100, such as a voice command like“stop follow” via a microphone. Alternatively or additionally, thecomputing device 202 may stop guiding 304 the guided pedestrian 100 incase that it determines that the guided person 100 does not continue tofollow the guiding direction provided via the output device 220 for morethan a predefined period, for example, 15 seconds. Alternatively oradditionally, a stopping criterion might be a deviation of the guideperson's 102 direction and/or distance with respect to the direction ordistance of the guided person 100 or a route that was previouslydetermined for the guided person 100. Various other stopping criteriamay be applied according to further envisioned usage situations.

Example 1 demonstrates a case where the portable pedestrian navigationsystem 200 achieves a navigation 304 of the pedestrian 100 withparticularly low hardware requirements. The computing device 202identifies 302 the moving object as a candidate guide entity 104 usingthe proximity sensor 210 and guides 304 the pedestrian 100 according tothe object movement using the output device 220. No further components,devices or units are required for the performance of the navigationsystem 200 and the guide person 102 can act as a guide without having tocarry a detectable electronic device such as a mobile phone, asmartphone or a tablet computer.

EXAMPLE 2

The pedestrian 100 is walking in an area where five further pedestrians104 are present in a radius of 100 meters around the pedestrian 100carrying the portable pedestrian navigation system 200. The navigationsystem 200 additionally comprises a wireless communications unitaccording to the Bluetooth standard which the computing device 202 usesfor broadcasting an availability request. In response to the broadcast,the navigation system 200 receives 300 one response from a smartphonecarried by one of the five further pedestrians 104. The navigationsystem 200 uses Bluetooth triangulation to determine the distance,velocity and direction of the responding device. As the computing device202 is configured to accept a candidate computing device 104 at anydistance within the range of the Bluetooth communications unit, itproceeds by performing a comparison of the determined velocity vector ofthe answering device to a previously determined route along which thecomputing device 202 is currently guiding 304 the pedestrian 100. Itdetermines that the direction of the velocity vector is withinplus-minus 10 degrees relative to the current navigation direction ofthe predetermined route, and that the velocity of the candidate device104 is within the desired velocity range of 40-100 meters per minute.Hence, the computing device 202 selects the responding candidate device104 as the selected guide entity 102 and continues to direct the guidedperson 100 along the route pursued by the selected device 102. In thealternative case that the computing device 202 receives no response, thecomputing device 202 continues to direct the guided person 100 along thepreviously determined walking route.

EXAMPLE 3

While the person 100 to be guided by the navigation system 200 iswalking in an area with a large number of further pedestrians 104 (e.g.30 further pedestrians 104 within a radius of 10 meters around thenavigated pedestrian 100), the navigation system 200 broadcasts anavailability request for guiding the pedestrian 100 and receives 300 aresponse from a large number of candidate computing devices 104 whichare available for guiding the pedestrian 100. In addition to otherapplicable eligibility criteria, the computing device 202 now applies aselection criterion to determine the most preferable candidate 104.Selection criteria may comprise, for instance, determining the candidatedevice 104 which is located at the shortest distance from the person 100to be guided or which ranks highest according to a score which iscalculated by the computing device 202 of the navigation system 200 orthe responding candidate computing device 104 based on the availableinformation about the candidate guide person 104 assigned to thecandidate computing device 104, such as an age, a gender or a walkingvelocity of the candidate guide person 104 or an identifier indicatingthe candidate guide person's 104 willingness to act as a guide.

EXAMPLE 4

The portable pedestrian navigation system 200 is guiding 304 the guidedperson 100 in accordance with a movement of a selected guide entity 102.The guide entity 102 is moving slightly faster than the guidedpedestrian 100 and moves out of the sensing range of the navigationsystem 200 after a while. As the navigation system 200 loses contact tothe guide entity 102, the computing device 202 first continues to guide304 the pedestrian 100 along the remaining route which was recorded fromthe movement of the guide entity 102. If the navigation system 200cannot restore the contact to the guide entity 102 until this point, itcontinues to guide 304 the guided person 100 along a route which waseither determined before the guiding sequence in accordance with themovements of the guide entity 102 who moved out of range was started, orit calculates a new route towards a known destination or a transitionalroute section towards a previously determined route.

EXAMPLE 5

The portable pedestrian navigation system 200 is guiding 304 the guidedperson 100 in accordance with the movement of a selected guide entity102 while the person 102 associated with the guide entity 102 notices abus stopping nearby and spontaneously decides to continue travelling bybus. The guide person 100 enters the bus and the bus leaves the stationwithout the guided pedestrian 100. The navigation system 200 thendetermines that the guide entity's 102 velocity exceeds the maximumacceptable velocity which was configured previously by the guidedpedestrian 100 and continues to guide 304 the guided pedestrian 100along a calculated route as previously described, for example, inexample 4.

EXAMPLE 6

The navigation system 200 is guiding 304 the guided person 100 inaccordance with the movements of a selected guide entity 102 while theguide person 102 associated with the guide entity 102 encounters atraffic light which is showing a “stop” signal. The navigation system200 determines that the velocity of the guide entity 102 has become zeroand starts observing the time during which the guide entity's 102velocity remains zero. The computing device 202 is configured to repeatthe identification sequence 302 for a candidate guide entity 104 in casethat the velocity of the selected guide entity 102 does not return tothe preferred velocity range within 30 seconds. However, the trafficlight changes its signal to “walk” after 18 seconds and the guide person102 continues to walk crossing the street. In response, the navigationsystem 200 continues to guide 304 the guided pedestrian 100 inaccordance with the movement of the selected guide entity 102.

In an alternative example, the traffic light signal does not change from“stop” for 46 seconds. After 30 seconds of halting, the navigationsystem 200 starts the sequence for identifying 302 a new candidate guideentity 104 for the purpose of determining a new selected guide entity102 which is able to guide 304 the pedestrian 100 wearing the portablepedestrian navigation system 200 with a velocity within the preferredwalking velocity range. The navigation system 200 identifies 302 anotherperson 104 who is waiting at the traffic light. However, the computingdevice 202 determines that the velocity of the new candidate 104 is alsozero, and therefore does not set the new candidate guide entity 104 asthe selected guide entity 102. After 46 seconds, the originally selectedguide entity 102 continues to walk crossing the street and thenavigation system 200 continues to guide 304 the guided pedestrian 100in accordance with the movement of the original selected guide entity102.

EXAMPLE 7

The portable pedestrian navigation system 200 is guiding 304 the guidedpedestrian 100 in accordance with the movement of the selected guideentity 102 as the guide person 102 associated with the selected guideentity 102 meets a friend, stops walking and starts talking for 5minutes. After a user-configured waiting time of 1 minute the navigationsystem 200 restarts the sequence for identifying 302 a candidate guideentity 104 in order to determine a new guide entity 102 which can serveas the selected guide entity 102. After 170 seconds the navigationsystem 200 senses that another pedestrian 104 is approaching whofulfills the eligibility criteria to become selected as a guide entity102. The navigation system 200 thus selects the new candidate guideentity 104 associated with the approaching pedestrian 104 as a newselected guide entity 102, but does not start guiding 304 the guidedpedestrian 100 in accordance with the movement of the new selected guideentity 102 because it has determined that the approaching pedestrian 104has not yet arrived and overtaken the guided pedestrian 100 in thedirection which was previously pursued by the guiding sequence inaccordance with the movement of the former selected guide entity 102.The navigation system 200 waits until the new selected guide entity 102arrives at a distance of, for example, 2 meters in the desired directionbefore the computing device 202 continues to guide 304 the guidedpedestrian 100 in accordance with the movement of the new selected guideentity 102.

EXAMPLE 8

While following the route taken by the selected guide entity 102, thecomputing device 202 determines using the proximity sensor 210 that amoving obstacle has moved into the guide's 102 path. The computingdevice 202 is configured to treat the environmental data received fromthe proximity sensor 210 with a higher priority than the walking routeof the guide 102 determined from the movement of the selected guideentity 102. In response, the computing device 202 starts calculating asafe evasive maneuver around the moving obstacle, which may includewaiting until the moving obstacle has passed by. The navigation system200 then continues to guide 304 the guided pedestrian 100 along theevasive route until the guided pedestrian 100 has reached the route ofthe guide entity 102 again and then proceeds to navigate 304 the guidedperson 100 in accordance with the movement of the selected guide entity102 as before.

EXAMPLE 9

The portable pedestrian navigation system 200 is additionally equippedwith a communications interface for a cellular telephony network. Thecomputing device 202 recognizes a candidate guide person 104 in theenvironmental data received from the proximity sensor 210. The computingdevice 202 then uses the cellular telephony interface to determine thatthe candidate guide person 104 is carrying a mobile phone which is alsoparticipating in the cellular telephony network. Via the cellulartelephony network, the computing device 202 receives 300 theinternational mobile subscribe identity (IMSI) of the SIM card which isassigned to the candidate guide person 104. The computing device 202then uses the received IMSI to request from the network provider whetherthe candidate guide person 104 is willing to act as a guide for anyperson 100 using the portable pedestrian navigation system 200. Theprovider looks up the requested information in a database and submitsthe requested information in a response to the portable navigationsystem 200. The computing device 202 then determines from the receivedresponse that the candidate guide person 104 is willing to act as aguide and eventually selects the candidate guide person 104 who iscontacted by the proximity sensor 210 as well as the mobile phonecarried by the candidate guide person 104 and contacted using the mobiletelephony interface as two alternative selected guide entities 102.

In this way, the computing device 202 is enabled to continue followingthe selected guide person 102 even if either the proximity sensor 210 orthe mobile telephony interface loses contact to the selected guideperson 102 or, respectively, the mobile phone carried by the selectedguide person 102. A further advantage demonstrated by this example isthat no additional software has to be installed on the mobile phone ofthe candidate guide person 104 for responding to an availability requestof the portable pedestrian navigation system 200.

EXAMPLE 10

The computing device 202 has detected a candidate computing device 104which fulfills all criteria for serving as the selected guide entity102, with the only exception that the destination of the guide person102 associated with the candidate computing device 104 is different fromthe destination selected by the guided pedestrian 100. However, thecomputing device 202 calculates or receives a calculated route to theguide's 102 destination and determines that the route calculated for theguide entity 102 runs close to a route which was calculated for thepedestrian 100 by not more than a user-configured distance of 200 metersalong a route section of a length which exceeds another user-configuredthreshold length of 100 meters of common route section. In response, thecomputing device 202 selects the candidate computing device 104 as theselected guide entity 102, continues to navigate 304 the guidedpedestrian 100 along the determined common route section in accordancewith the movement of the selected guide entity 102 and eventuallyproceeds with identifying 302 a new candidate guide entity 104 andguides 304 the guided person 100 further along a calculated route if nonew candidate guide entity 104 is available or in accordance with themovement of a new selected guide entity 102 if a new candidate guideentity 104 is found to be eligible to serve as the selected guide entity102.

FIG. 2 is a schematic block diagram of an exemplary portable pedestriannavigation system 200. The system 200 comprises a computing device 202,a proximity sensor 210 and an output device 220. The computing device202 comprises at least a processor 204, memory 206 and interfaces forcommunicatively connecting the proximity sensor 210 and the outputdevice 220. The proximity sensor 210 and the output device 220 arecommunicatively connected to the respective interfaces of the computingdevice 202. Non-limiting examples for the proximity sensor 210 includean optical sensor (e.g., a digital camera), an infrared sensor, a radarsensor, an ultrasonic sensor, or a combination thereof. Non-limitingexamples for the output device 220 include a tactile actor; aloudspeaker; a visual display; or a combination thereof.

All components of the pedestrian navigation system 200 are portable incombination by a pedestrian 100. This includes typical hardwarespecifications such as weight limitations and battery power supply. Thecomputing device 202 may comprise, without limitation, a cell phone, asmartphone, a tablet computer or another mobile computer systemcomprising dedicated pedestrian navigation hardware. The proximitysensor 210 and/or the output device 220 may be integrated in clothes oraccessories to be worn by the pedestrian 100, like bracelets or shoeswith proximity sensors 210, positioned on both arms and legs or shoes,and actors, vibrators or other tactile output devices 220 capable ofindicating a direction to the pedestrian 100.

The computing device 202 has stored in its memory 206computer-executable instructions which, when executed by the processor204, cause the computing device 202 to receive 300 environmental data atleast from the proximity sensor 210; based on the environmental data,identify 302 a candidate guide entity 104 near the pedestrian 100; andbased on the environmental data, use the output device 220 for guiding304 the pedestrian 100 in accordance with a movement of the identifiedcandidate guide entity 104 as a selected guide entity 102 as describedherein. A guide entity 102, 104 may be a guide person 102, 104 or aguide computing device 102, 104.

The system may comprise further devices and units which arecommunicatively and/or controllably connected to the computing device202, examples of which include, without limitation, a wirelesscommunications unit (e.g. a Bluetooth unit comprising chipset,transceiver and antenna), a location sensor (e.g. a receiver for asatellite-based positioning system such as GPS, Galileo, GLONASS,Beidou, etc.), and/or a data exchange interface, including a suitableinterface for receiving a navigation specification such as a microphone,a tactile input device, a wireless communications unit, a wiredcommunications unit or a combination thereof. In these implementations,the computing device 202 is adapted for performing the identification302 of the candidate guide entity 104 and/or the guidance of thepedestrian 100 in accordance with a movement of the candidate guideentity 104 as a selected guide entity 102 further based on informationreceived from such further devices and units.

FIG. 3 is a schematic representation of a method for operating aportable pedestrian navigation system 200 to be ported by a pedestrian100 as described herein. The method comprises, using the computingdevice 202 of the system, receiving 300 environmental data at least fromthe proximity sensor 210; based on the environmental data, identifying302 a candidate guide entity 104 near the pedestrian 100; and based onthe environmental data, use the output device 220 for guiding 304 thepedestrian 100 in accordance with a movement of the identified candidateguide entity 104 as a selected guide entity 102.

The step of receiving 300 environmental data may include receiving theenvironmental data from other sources such as a wireless communicationssystem. The step of identifying 302 a candidate guide entity 104 maycomprise one or more sub-steps such as evaluating the environmental dataunder one or more eligibility criteria such as an age of a candidateguide person 104 associated with the detected candidate guide entity104. The step of guiding 304 the pedestrian 100 may comprise one or moresub-steps such as calculating a route segment for avoiding a temporaryobstacle. The method may comprise additional steps such as reporting,upon completion of the guidance, characteristics of the guidance (e.g.time of completion of the guidance, name of the guide person 102 and/orthe guided pedestrian 100, length of the route along which thepedestrian 100 was guided by the guide entity 102, etc.) to a computingsystem for billing or rewarding the available guide person 102.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The invention claimed is:
 1. A portable pedestrian navigation system forcarrying by a pedestrian, the system comprising a computing device, aproximity sensor and an output device, the proximity sensor and theoutput device being communicatively coupled to the computing device, thesystem further comprising a processor and memory storingcomputer-executable instructions which, when executed by the processor,cause the system to perform functions of: receiving environmental dataat least from the proximity sensor; based on the environmental data,identifying a candidate guide entity near the pedestrian, wherein theguide entity is a person; and based on the environmental data, using theoutput device for guiding the pedestrian in accordance with a movementof the identified candidate guide entity as a selected guide entity,wherein the guiding comprises: providing a signal to the pedestrianwhich indicates a direction into which the pedestrian would have to walkto arrive at a current place of the guide entity while avoiding one ormore obstacles avoided by the guide entity to reach the current place ofthe guide entity.
 2. The system of claim 1, further comprising awireless communications unit, the wireless communications unit beingcommunicatively coupled to the computing device, the memory storingfurther instructions for receiving the environmental data from thecommunications unit, the identification of the candidate guide entitycomprising: generating an availability request for guiding thepedestrian; broadcasting the availability request using the wirelesscommunications unit; in response to the broadcast, receiving a responsefrom a candidate computing device; and based on the response, selectingthe candidate computing device as the selected guide entity.
 3. Thesystem of claim 2, the wireless communications unit having a maximumrange between 10 and 250 meters.
 4. The system of claim 2, the wirelesscommunications unit comprising a communications interface according toone of the following: IEEE 802.15; IEEE 802.11; Wireless USB; wirelessad hoc network; DASH7; RuBee; Z-Wave; a mobile telecommunicationsstandard; or a combination thereof.
 5. The system of claim 2, the memorystoring further instructions for detecting a coincidence of position,direction and/or velocity between a movement of an object detected usingthe proximity sensor and a movement of the candidate computing device,and instructions for performing the guidance in accordance with themovement of the detected object as an auxiliary guide entity.
 6. Thesystem of claim 1, the memory storing further instructions forperforming the identification of the candidate guide entity as a personby analyzing the environmental data with a person recognition algorithm.7. The system of claim 1, the memory storing further instructions forperforming the guidance of the pedestrian in accordance with a route tobe taken by the pedestrian, the identification of the candidate guideentity comprising determining, based on the environmental data, whethera route expected to be taken by the candidate guide entity coincideswith at least a section of the route to be taken by the pedestrian. 8.The system of claim 1, the memory storing further instructions forreceiving a preference information of the pedestrian and performing theguidance of the pedestrian in accordance with the preferenceinformation.
 9. The system of claim 1, the memory storing furtherinstructions for determining, in case that an updating condition isfulfilled, an updated selected guide entity by repeating theidentification of the candidate guide entity, the updating conditionrelating to a detection of one of the following events in conjunctionwith the selected guide entity: an interruption of movement for morethan a predefined period; a deviation from an expected route by morethan a predefined distance; a movement with a velocity out of apredefined velocity range; an approach of a prospective point ofseparation from the pedestrian by less than a predefined distance; or acombination thereof.
 10. The system of claim 1, the memory storingfurther instructions for performing the identification of the candidateguide entity based on one of the following: a walking velocity of acandidate guide person; a timestamp indicating data currentness ofinformation related to the candidate guiding person; a length of a routesection on which the candidate guide person is expected to be availablefor guiding; a potential time and/or place of encounter of thepedestrian with the candidate guide person; or a combination thereof.11. The system of claim 1, the memory storing further instructions forperforming the guidance additionally based on a route assigned to theguide entity and/or a route calculated for the pedestrian in case theguidance cannot be continued based on the environmental data.
 12. Thesystem of claim 11, the memory storing further instructions forperforming the guidance based on the route calculated for the pedestrianonly if the guidance cannot be continued based on the route assigned tothe guide entity.
 13. The system of claim 1, further comprising alocation sensor, the location sensor being communicatively coupled tothe computing device, the memory storing further instructions forreceiving location data from the location sensor and performing theguidance and/or the identification using the location data.
 14. Thesystem of claim 1, further comprising an interface for receiving anavigation specification, the interface being communicatively coupled tothe computing device and comprising one of the following: a microphone;a tactile input device; a wireless communications unit; a wiredcommunications unit; and a combination thereof, the computing devicebeing adapted for performing the guidance and/or the identificationbased on the received navigation specification.
 15. The system of claim1, the proximity sensor comprising one of the following: an opticalsensor, an infrared sensor, a radar sensor, an ultrasonic sensor; or acombination thereof.
 16. The system of claim 1, the output devicecomprising one of the following: a tactile actor; a loudspeaker; avisual display; or a combination thereof.
 17. A method of operating aportable pedestrian navigation system for carrying by a pedestrian, thenavigation system comprising a computing device, a proximity sensor andan output device, the proximity sensor and the output device beingcommunicatively coupled to the computing device, the computing devicecomprising a processor and memory, the memory storingcomputer-executable instructions which, when executed by the processor,cause the computing device to: receive environmental data at least fromthe proximity sensor; based on the environmental data, identify acandidate guide entity near the pedestrian, wherein the guide entity isa person; and based on the environmental data, use the output device forguiding the pedestrian in accordance with a movement of the identifiedcandidate guide entity as a selected guide entity, wherein the guidingcomprises: providing a signal to the pedestrian which indicates adirection into which the pedestrian would have to walk to arrive at acurrent place of the guide entity while avoiding one or more obstaclesavoided by the guide entity to reach the current place of the guideentity.
 18. The method of claim 17, wherein the system further comprisesa wireless communications unit, the wireless communications unit beingcommunicatively coupled to the computing device, the method furthercomprising receiving the environmental data from the communicationsunit, the identification of the candidate guide entity comprising:generating an availability request for guiding the pedestrian;broadcasting the availability request using the wireless communicationsunit; in response to the broadcast, receiving a response from acandidate computing device; and based on the response, selecting thecandidate computing device as the selected guide entity.
 19. The methodof claim 18, further comprising detecting a coincidence of position,direction and/or velocity between a movement of an object detected usingthe proximity sensor and a movement of the candidate computing device,and performing the guidance in accordance with the movement of thedetected object as an auxiliary guide entity.
 20. A computer programproduct for operating a portable pedestrian navigation system forcarrying by a pedestrian, the navigation system comprising a computingdevice, a proximity sensor and an output device, the proximity sensorand the output device being communicatively coupled to the computingdevice, the computing device comprising a processor and memory, thecomputer program product comprising a non-transitory computer-readablemedium and a set of computer-executable instructions incorporatedtherewith, the computer-executable instructions being adapted to causethe computing device, when executed by the processor, to: receiveenvironmental data at least from the proximity sensor; based on theenvironmental data, identify a candidate guide entity near thepedestrian, wherein the guide entity is a person; and based on theenvironmental data, use the output device for guiding the pedestrian inaccordance with a movement of the identified candidate guide entity as aselected guide entity, wherein the guiding comprises: providing a signalto the pedestrian which indicates a direction into which the pedestrianwould have to walk to arrive at a current place of the guide entitywhile avoiding one or more obstacles avoided by the guide entity toreach the current place of the guide entity.